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VK5QX > TECH 04.02.04 21:45l 81 Lines 2580 Bytes #999 (0) @ WW
BID : D30806VK5QX
Read: GUEST DB0FHN
Subj: Re: Physics. 3 Questions.
Path: DB0FHN<DB0FOR<DB0SIF<DB0EA<DB0RES<ON0AR<7M3TJZ<KP4IG<WB0TAX<ZL2TZE<
VK5UJ<VK5BRC<VK5SPG<VK5TTY<VK5LZ
Sent: 040204/0140Z @:VK5LZ.#ADL.#SA.AUS.OC #:12998 [Elizabeth] $:D30806VK5QX
From: VK5QX@VK5LZ.#ADL.#SA.AUS.OC
To : TECH@WW
BLACK OR WHITE ?
There had been some comment on the matter of resultant temperatures
according to the paint colour of a car.
____
" From: G4XNH@GB7YKS.#19.GBR.EU
To : TECH@WW
VK3ABK wrote:-
____
By the way, I am disapointed (sic) with the non-replies to a comment from
Ralph, VK2ZRG, about a black car in a hot country. 'To Man' - 'More
stupidity'.
Has anyone wandered through a supermarket car park on a sunny day,
touching
the roof of various coloured cars? Of course not; but try it for science.
____
I well remember Mr Cook our Science teacher, having a stoppered black can
and a white can on the front bench with bunsen burners under them. After a
while one of them imploded. Guess which one. This was accompanied by a
lecture on kepis and white suits in deserts and how colours make a
difference in temperature extremes. It made the desired impression.
73 - Jeff, G4XNH @ GB7YKS "
__________
I well remember several tests carried out by measurement of surface
temperatures on cars.
At the time I was located at Woomera, a town in the far north of the State
of South Australia where summer temperatures can be quite extreme.
I do not remember what the actual resultant readings were, however, I can
state quite categorically that the surface temperatures were markedly
higher where the surfaces were of the darker colours.
The differences were certainly such that one could well think twice about
the in-advisability of buying a dark coloured vehicle.
It was interesting to also note the comparison, on the same vehicle, where
it had a dark coloured bonnet (hood) and a light coloured roof.
In these instances the "theory" seemed to be well proven.
"Two toned" cars, where a white roof was common, seem to have now gone out
of fashion.
I have to wonder why this should be so in a climate where high summer
temperatures are the norm.
Incidentally, here in Adelaide we have just experienced the coolest
January since 1992. The weather has been exceptionally nice with top
temperatures mainly around the high 20's.
Now that February has commenced it seems that the weather is going to try
and make up for that lovely respite as the levels creep up to into the mid
to high 30's with 38 degrees Celsius (100.4 F) forecast within the next
couple of days.
Fortunately, as has been previously mentioned, these higher temperatures
can be tolerated reasonably well as we generally have quite low humidity
levels.
Regards,
Ian
__________
73 de Ian, VK5QX
@ VK5LZ.#ADL.#SA.AUS.OC
04 February 2004
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